基于体烧蚀模型的后效推力预示方法

Prediction Method of Tail-off Thrust Based on Bulk Ablation Model

为了获得固体火箭发动机的高空后效推力,提出了基于气相环境双区体烧蚀模型。考虑粒子侵蚀热效应,将发动机熄火后燃烧室的瞬时压强和温度与绝热层烧蚀放气量进行耦合迭代的后效推力预示方法。根据某固体火箭发动机燃烧室绝热层的结构布局和工作参数,计算得到绝热层的碳化烧蚀率、烧蚀质量损失速率、温度场分布、炭化层孔隙结构和发动机高空后效推力,后效推力曲线与发动机遥测数据包线上限吻合,验证了预示方法的可行性。

A prediction method is proposed to calculate high altitude tail-off thrust of solid rocket motor.Based on bulk ablation model with double zones in gas phase environment,the heat effect of particle erosion was considered.The pressure and temperature of the combustion chamber after burnout were coupled with the total ablation mass loss of the insulator.According to the insulator structure layout and the working parameters of a solid rocket motor,the ablation rate,the mass loss rate,the temperature distribution and the carbon layer porous structure were obtained.The tail-off thrust was obtained also and the result was consistent with the upper limit of the telemetry data envelope,showed that the prediction method is effective.